Relating to the motion of objects through space and time. Including concepts such as acceleration (thrust and gravity), mass, collision response, friction and more.

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26 views

JBullet move object rigidbody in code?

I am trying to move an object's Transform (of a coded class, these are for the rendering engine), then convert it into a JBullet Transform. After that, I try to apply any movement to the JBullet ...
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1answer
584 views

Spritekit - gradually apply force vector in different direction (space ship turning)

I have a space ship that I'm applying a force vector to using a joystick for control. I would like this to smoothly fly around when I'm switching directions.. Exactly like minisquadron if you've ...
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0answers
25 views

Simulating wind effects in a tree, falling fruit etc [on hold]

I have a project that requires me to simulate trees moving in the wind. Can anyone share any examples, regardless of software? Would it be better to use a 2d or 3d framework?
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2answers
131 views

2D Physics: What happens with torque when center of mass changes?

Novice programmer and explorer of simple 2D physics, here. I have a simple 2D object made up of two rigid bodies connected at a fixed joint. The two rigid objects can rotate freely about that fixed ...
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2answers
1k views

Effects of collisons: broken glass, damaged cars, how are they created?

My question is related in particular to achieving the effects of collision in game engine, how is this done? I have searched a bit, read from the internet and went through a few tutorials, and saw ...
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1answer
258 views

Bullet 3D Physics Objects Not Rotating?

So I've got Bullet 3D controlling the motion of objects rendered with DirectX. In the clipping below I've got 2 identical rectangles & 5 balls. The lowest rectangle has a mass of 0 and doesn't ...
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3answers
94 views

Calculate intersect point / aim point

I'm working on a simple game, and I need to calculate the position to aim. Since my math days are a bit behind me, I put together a simple example to illustrate: So given that I know the position ...
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2answers
76 views

Why doesn't this 2d physics calculation yield the desired jump height?

I found a formula for gravity and jumping in this article: http://error454.com/2013/10/23/platformer-physics-101-and-the-3-fundamental-equations-of-platformers/ I implemented this formula and ...
186
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10answers
50k views

When should I use a fixed or variable time step?

Should a game loop be based on fixed or variable time steps? Is one always superior, or does the right choice vary by game? Variable time step Physics updates are passed a "time elapsed since last ...
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2answers
54 views

Moving OBB vs. triangle intersection test

Requirements: to write a test function that, given a moving OBB (oriented bounding box) and a triangle, returns true whenever the OBB hits the triangle. The OBB is described by its half extents (h1, ...
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1answer
198 views

LibGDX Bounding Rectangles

I'm creating some rectangles surrounding my sprites for my player and bullet class to detect collisions with the overlaps method in Intersector class of LibGDX. I have a question: When I instantiate ...
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0answers
18 views

Leapfrog integration vs Euler integrator

I am looking at various integration methods for my n-body simulation and I'm slightly confused about actual implementation of leapfrog integration. According to the wikipedia page leapfrog method is ...
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1answer
438 views

Is there a javascript physics engine that does not require canvas? [closed]

I just need a really simple and small physics engine for squares or circles that moves images using javascript. For the project that I am working on, I can't use canvas, so I will be moving the images ...
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1answer
48 views

LibGDX - Executing 2 different touchDown events in the same method

On the bottom left of my screen is a circle with an Arrow and on the bottom right is a circle with a gun. If the player is in jetpack mode and the Arrow "button" is clicked he flies like flappy bird ...
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2answers
311 views

Can Unity 5 or Unreal Engine 4 do computationally identical physics simulation across platforms?

In order to use certain approaches to multiplayer physics, it requires that the clients calculate exactly the same values for physics simulations. That "exactly" is a very big word here and goes all ...
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1answer
103 views

Unity 2D - Pixel perfect movement using physics

I'm trying to make a game in the style of many NES games and I'd like object movement to do two things: I want to move an exact number of pixels per update. I want, for lack of a better term, ...
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1answer
45 views

How to use friction to bring object to a stop in a simple 2D platformer?

I'm coding the physics for a little platformer I'm making but I'm not sure how to design a friction calculation that does what I expect. When running along a platform I want the player's character to ...
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1answer
106 views

Custom arcade physics rate (e.g. bullet time)?

Is there a way to modify the rate that physics is applied, either globally or on a per-sprite basis in Phaser? That is, how can I slow down or speed up the rate at which sprites move around, or fall ...
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1answer
21 views

CGVectorMake to move SKNode at a certain speed towards the middle of screen?

I am trying to launch my ball sprite towards the middle of the screen at the same speed every time I launch it. let vel: CGFloat = 1000 dx = size.width / 2 - ball.position.x dy = vel - size.height / ...
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4answers
67 views

How do I figure out if a point is infront or behind my vehicle?

I need to figure out whether a point is infront or behind my vehicle. I have the vector of it's position, forward direction. So far I have tried finding the vector perpendicular to its forward ...
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1answer
77 views

Moving CCNode with constant speed in cocos2d

I want to move the object (CCNODE) with constant speed in any direction , what i have did till now is applied a force to object at start to get it moving and set elasticity as 1 and friction as 0 to ...
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2answers
341 views

3D collision physics. Response when hitting wall, floor or roof

I am having problem with the most basic physic response when the player collide with static wall, floor or roof. I have a simple 3D maze, true means solid while false means air: bool ...
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1answer
50 views

Immovable object impact physics

I am trying to do some physics calculations from scratch, and as a result am creating a small bouncing ball example. However, I have some issues getting correct results from my impact physics when the ...
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1answer
34 views

Box2D: Making it Determinsitic?

From articles on the web, I found that floating point math generally has accuracy of at least 6 digits. With this in mind, is it possible to make Box2D which uses floats fully deterministic through ...
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1answer
60 views

Spherical Collision

I have a made spherical collision system which creates a major problem, the balls gets stuck to each other on high speed and sometime with low speed collisions. I researched a lot but I couldn't found ...
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0answers
70 views

How do I implement realistic recovery from weapon recoil?

I want to create an equation determining how fast a gun recovers back to its center after it has fired. I have a weapon system functioning based on constants (recoil amount, bullet spread, etc.) ...
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3answers
2k views

Collider2D and Rigidbody2D, how do they work?

I have been learning JavaScript and Unity for a week now. I learned how to make Cube as a Ground and another Cube as a player and I used this code to make the Player Cube move forward and backward and ...
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1answer
187 views

Estimate the time it takes for an object to travel from point A to point B

I have an object with vec2 position, velocity, and destination with 2 variables maxspeed and acceleration. In each step, its position is calculated as follows: vec2 desiredVel = destination - ...
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1answer
211 views

Grid collision - finding the location of an entity in each box

I am trying to implement grid-based collision in a 2d game with moving circles. The canvas is 400x400 pixels. Below you can see the code for my Grid class. What I want it to do is check inside which ...
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4answers
373 views

What is the easiest way to make an object follow the edge of a sprite?

I have a rounded rectangle sprite and another sprite that's just a circle. I want the center of the circle to follow the edge of the rounded rectangle. Is there any easy way to accomplish this task? ...
4
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1answer
1k views

2D game - Missile shooting problem on Android

I have to make a tank that sits still but moves his turret and shoots missiles. As this is my first Android application ever and I haven't done any game development either, I've come across a few ...
0
votes
1answer
58 views

Making a gameObject push the player

I am working on a Unity 3D game for Oculus and I have problems with making my objects to apply physics on a player. So getting rid of a CharacterController and using something like a rag doll is not ...
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1answer
45 views

Gravity Simulation failing at short distances

I have a 2D space simulation with gravity acting on three bodies (e.g. sun and 2x planets). The simulation seems pretty stable with RK4 (was unstable with Euler). The problem arises if the orbit of ...
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3answers
150 views

Formula for Planetary Alignment

I am attempting to create a game where there is a universe of two 16-bit addresses ranging from -32768, -32768 to 32767,32767, or in hexadecimal, each value can run from $8000 to $FFFF then 0 to ...
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2answers
74 views

Why does this simple if-statement that checks my main characters state never get called (Java/LibGDX)?

Been working on this for a while - basically I want my player to perform a front flip when he jumps (screen tap -> player jumps). I wrote the animation class Animator (extends Player implements ...
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1answer
41 views

Rotate a plane defined by its normal and its distance

First apologies for the amount of pictures, it's a bit hard trying to explain my problem without pictures. Hope I've provided all the relevant code. If you feel you want to know about how I am doing ...
2
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0answers
242 views

Inverse Dynamics How to [closed]

I have some motion capture data (kinect) that records all body joints (32fps) and I want to take particular positions (for example when a person moves both of his hands up in the sky in celebration ...
2
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1answer
57 views

How to restrict jumping to a single jump?

I'm making a VolleyBall game in HTML5 with PandaJs GameEngine and plugin is used physics and Box2D. The problem is that players can jump, but they can jump over the net with multiple jumps. I have ...
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3answers
919 views

Can I change shape of a rigid body after it created in Bullet3D?

I'm beginning Bullet3D. Can I change collision shape of a rigid body after it created? A rigid body accepts a collision shape when it's creating, but it's hard to find options changes the collision ...
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0answers
84 views

Anti-Roll bar doesn't work

I'm making a racing game in Unity that has trucks as vehicles. For the truck movement, I'm using WheelColliders. After some testing, I found out that after a certain speed (~60km/h), turning made the ...
2
votes
1answer
114 views

Frame independent buoyancy using Substepping

I am having trouble with a frame independent buoyancy force using substepping in Unreal Engine 4. The original problem (which I am attempting to solve using substepping) is that when you apply a ...
4
votes
2answers
273 views

Jelly ground collision

For fun I am trying to replicate the mechanics from The Floor is Jelly. So far I have successfully created "jelly islands/blocks" which are represented by an array of points and then drawn by using ...
2
votes
1answer
107 views

Unintended sliding blocks Unity (5) physics

A game I'm working on right now relies on the Unity physics system for collisions, gravity etc. This all works well except for one strange thing. When an explosive is placed on a stone cube, it'll ...
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0answers
48 views

How can I handle ball interaction with lanes in a pinball game?

In a pinball game, how can I handle collision or constraints on the ball for convincing movement on those highway rails/tracks? I assume using physics and a mesh collider would not work, even when ...
0
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1answer
41 views

Dragging an object and moving it back to it's original position on release?

I'm making a small game, and I'm trying to add this mechanic where if you click on an object and move it, then you release the object it will snap back to it's original position. Currently, each ...
0
votes
1answer
55 views

How to reference the right object in Unity

So, I'm developing this small 2D project where I have a sphere that detects if objects get close to it from three different directions. I have successfully found a way to detect if an object ...
0
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1answer
38 views

Getting distance between point of an object and another object in Unity

First, I'd like to apologize because this is a very basic and repetitive question, but I am completely new to game development. I understand that I can find a distance between two objects using: ...
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2answers
116 views

Realistically drivable car

I want my car to be realistically drivable (like in real life...) Unfortunately all I did so far is Rotate the whole vehicle using A and D; and AddForce in forward-backward direction using W and S ...
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3answers
204 views

How to implement accurate frame-rate-independent physics?

So, I have been working on a project for a while now and recently stumbled across a problem: The common approach to frame-rate independent physics is to either use a fixed update interval (ie. Unity) ...
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3answers
622 views

How can I model the physics of an air blower?

I want to model simple lottery machine, it has got a bottom blower. Do you know how can I get force applied to object above blower by air from blower, or equations to model this behavior? Red ...